I am beginning to have a few suspicions regarding embedded window antennas. In my G35 I have an antenna amplifier. This is switched. So if you install an aftermarket radio and not hook the amplifier up to the ignition circuit from the new radio, it will never power on. I also suspect that it is very possible that if you turn the factory head unit to a different function, such as CD or Satellite radio, it very well my turn off the antenna amplifier since it is not in use. Both of these situations would make using the factory embedded antenna unsuitable for anything but the factory radio. Don't know if this is the case with all embedded antennas, but just my 2 cents.

I have a Visteon HD Radio in my 1999 Grand Marquis, which also has an embedded antenna in the rear window. I have great reception in CF, RR, and using the app included with Mitch's drivers. Have you tried using a different Motorola antenna cable from the HD unit to your antenna?

So i'm thinking of cutting the white wire out of the harness and powering it to a 12v connection?
or do you guys think it'll work if i tap it off the same Directed HD radio power connections;
red wire, yellow wire, or both.